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zac1981c20

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zac
Truck Year
1981
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c20
Engine Size
350
Hello everyone I’m zac and I’m 21 I’ve been a mechanic for about three and a half years and I’m new to the square body family. I just bought a 1981 Chevy c20 with a 350 I couldn’t get much history from the guy I bought it from except that the motor is 3 years old body has about 180xxx. Anyhooter what I’ve done to the truck so far is plug’s , wires, cap and rotor, oil pressure sending unit, and Speedo cable. Here comes my current issue at the end of the work day today I did the cap and rotor after doing the cap and rotor the truck idles better than it has for the most part but when I tried to pull out of the shop the moment theres any load more than the verry min to get moving it after fires like crazy and just wants to stall and actually will stall with enough throttle it stalled twice on me on my way home. Once I got into the driveway I hopped out and tried to see if the distributor just needed a little adjustment but it died the moment I got near it at all and wouldn’t restart. I’ve got ideas but I’m not sure if I’m even close I apologize for the lengthy post but I could sure use some assistance
 

82sbshortbed

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I'd check the wires and make sure they're in the right order. I had similar issue and I had 3 and 5 swapped. Fixed when I put them right.
 

zac1981c20

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Update I went out and checked wires and everything is where it should be still wouldn’t start
 

zac1981c20

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I have not yet I’ve been meaning to I’m gonna have to rent a timing gun
 

zac1981c20

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zac
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1981
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350
Update I went out this morning and still no start. Pulled a plug wire and found I’m getting spark but it seems to be very erratic. I pulled the cover off the coil to double check the grounds are good and everything seems to be how it should be
 

dvdswan

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Welcome to the site.

What did you gap the plugs at? What did the distributor look like when you had the rotor off? Was there any play in the in the shaft? Instead of renting a timing gun, just buy one. If you are going to own older vehicles it will be handy to have one.

Check the fuel filter also. What type of carb is it? Q-jet, holley, carter, etc. If it's a Q-jet the filter is at the fuel inlet line, easily forgotten to replace by folks that don't know it's there.
 

mtbadbob

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If you're getting spark, you need to check fuel delivery. I was thinking ignition module also.
 

zac1981c20

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1981
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i never had the distributor actually out when I did the cap and rotor the plugs are at .035
I did end up buying a timing gun this morning and a whole new distributor, I checked the shaft to see if it had play when I had the old one out and it has a little up and down but from what I have read that is normal nothing side to side.
Fires right up now runs ok. Just need to mess with timing now I think.
It’s an Eddlebrock carb.
What’s the chance it was just something internal on the coil?
I’ve been trying to think and I’m struggling since I do have a concussion at the moment I do apologize
 

Randy and Easton

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You are definitely on the right track with the distributor and timing. See where you are then.

Oh, welcome to the site Zack, we love pictures

Randy and Easton
 

zac1981c20

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1981
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Engine Size
350
Thank you all! I appreciate the help I’m sure I’ll need more in the future
 

Corvette Ed

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Welcome aboard from East Tennessee. Good luck with the troubleshooting, If you’re getting spark then I’d see if it’ll fire on a few shots of starter fluid.
 

Grumpy

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350
Zac, welcome to the wonderful world of mechanics. As a Journeyman of thirty-plus years, I can guarantee if you become a solid mechanic, you will always have work (all the guys with real brains are doing something else.) You will never be rich, yet if you play your cards right, you will never be poor.

As for your truck, I suggest you verify the quality of spark and then fuel supply. The HEI is quite idiot-proof, as GM back in the day still kinda gave a rats-pitoot about the customer. Underneath the top cap of the distributor cap are flat blades of tin that connect to the "BAT" and "TACH" wires - these will flex over time and break. I agree with mtbadbob in the possibility of a poor ignition module. Check to make sure 5 and 7 are not swapped - a Chevy will still start (hard) and run, but it will pop and fart under the slightest load. Verify the quality of your ignition wires - I myself have induced problems after being a little too Western with the boots.

As a habit, I never use ether/starting fluid to spray down the carburetor when trying start - that stuff does not like compression or ignition, and if employed excessively will cause sever damage o the engine. My personal choice is a good brake cleaner with the little red straw extension.

No one has asked yet if your timing chain is loose. A quick (though not entirely accurate) check is to remove the distributor cap a crank the engine at the crank pulley back and forth. I have seen Chevys move fifteen degrees before the distributor starts to move - a clear sign the cam may have skipped.
Nonetheless, verify the timing.

You are in good hands the others helping you here.
 

89Suburban

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Good job Zac. Keep at it.
 

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